Re: [PATCH v4 3/6] KVM: selftests: Introduce __kvm_pmu_event_filter to improved event filter settings

On Mon, Jul 17, 2023 at 02:23:40PM +0800, Jinrong Liang ljr.kernel@gmail.com wrote:

From: Jinrong Liang cloudliang@tencent.com

Add custom "__kvm_pmu_event_filter" structure to improve pmu event filter settings. Simplifies event filter setup by organizing event filter parameters in a cleaner, more organized way.

Signed-off-by: Jinrong Liang cloudliang@tencent.com

.../kvm/x86_64/pmu_event_filter_test.c | 179 +++++++++--------- 1 file changed, 87 insertions(+), 92 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c index 5ac05e64bec9..ffcbbf25b29b 100644 --- a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c +++ b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c @@ -28,6 +28,10 @@ #define NUM_BRANCHES 42 +/* Matches KVM_PMU_EVENT_FILTER_MAX_EVENTS in pmu.c */ +#define MAX_FILTER_EVENTS 300 +#define MAX_TEST_EVENTS 10

/*

• This is how the event selector and unit mask are stored in an AMD
• core performance event-select register. Intel's format is similar,

@@ -69,21 +73,33 @@ #define INST_RETIRED EVENT(0xc0, 0) +struct __kvm_pmu_event_filter {

• __u32 action;
• __u32 nevents;
• __u32 fixed_counter_bitmap;
• __u32 flags;
• __u32 pad[4];
• __u64 events[MAX_FILTER_EVENTS];

+};

/*

• This event list comprises Intel's eight architectural events plus
• AMD's "retired branch instructions" for Zen[123] (and possibly
• other AMD CPUs).

*/ -static const uint64_t event_list[] = {

• EVENT(0x3c, 0),
• INST_RETIRED,
• EVENT(0x3c, 1),
• EVENT(0x2e, 0x4f),
• EVENT(0x2e, 0x41),
• EVENT(0xc4, 0),
• EVENT(0xc5, 0),
• EVENT(0xa4, 1),
• AMD_ZEN_BR_RETIRED,

+static const struct __kvm_pmu_event_filter base_event_filter = {

• .nevents = ARRAY_SIZE(base_event_filter.events),
• .events = {

• EVENT(0x3c, 0),
  

• INST_RETIRED,
  

• EVENT(0x3c, 1),
  

• EVENT(0x2e, 0x4f),
  

• EVENT(0x2e, 0x41),
  

• EVENT(0xc4, 0),
  

• EVENT(0xc5, 0),
  

• EVENT(0xa4, 1),
  

• AMD_ZEN_BR_RETIRED,
  

• },

}; struct { @@ -225,47 +241,11 @@ static bool sanity_check_pmu(struct kvm_vcpu *vcpu) return !r; } -static struct kvm_pmu_event_filter *alloc_pmu_event_filter(uint32_t nevents) -{

• struct kvm_pmu_event_filter *f;
• int size = sizeof(*f) + nevents * sizeof(f->events[0]);
• f = malloc(size);
• TEST_ASSERT(f, "Out of memory");
• memset(f, 0, size);
• f->nevents = nevents;
• return f;

-}

-static struct kvm_pmu_event_filter * -create_pmu_event_filter(const uint64_t event_list[], int nevents,

• 	uint32_t action, uint32_t flags)
  

-{

• struct kvm_pmu_event_filter *f;
• int i;
• f = alloc_pmu_event_filter(nevents);
• f->action = action;
• f->flags = flags;
• for (i = 0; i < nevents; i++)

• f->events[i] = event_list[i];
  

• return f;

-}

-static struct kvm_pmu_event_filter *event_filter(uint32_t action) -{

• return create_pmu_event_filter(event_list,

• 		       ARRAY_SIZE(event_list),
  

• 		       action, 0);
  

-}

/*

• Remove the first occurrence of 'event' (if any) from the filter's
• event list.

*/ -static void remove_event(struct kvm_pmu_event_filter *f, uint64_t event) +static void remove_event(struct __kvm_pmu_event_filter *f, uint64_t event) { bool found = false; int i; @@ -313,66 +293,70 @@ static void test_without_filter(struct kvm_vcpu *vcpu) } static void test_with_filter(struct kvm_vcpu *vcpu,

• 	     struct kvm_pmu_event_filter *f)
  

• 	     struct __kvm_pmu_event_filter *__f)
  

{

• struct kvm_pmu_event_filter *f = (void *)__f;
• vm_ioctl(vcpu->vm, KVM_SET_PMU_EVENT_FILTER, f); run_vcpu_and_sync_pmc_results(vcpu);

} static void test_amd_deny_list(struct kvm_vcpu *vcpu) {

• uint64_t event = EVENT(0x1C2, 0);
• struct kvm_pmu_event_filter *f;

• struct __kvm_pmu_event_filter f = base_event_filter;

• f = create_pmu_event_filter(&event, 1, KVM_PMU_EVENT_DENY, 0);
• test_with_filter(vcpu, f);
• free(f);

• f.action = KVM_PMU_EVENT_DENY;
• f.nevents = 1;
• f.events[0] = EVENT(0x1C2, 0);
• test_with_filter(vcpu, &f);

This overwrite all members. We can use designated initializer. struct __kvm_pmu_event_filter f = { .action = KVM_PMU_EVENT_DENY, .nevents = 1, .events = { EVENT(0x1C2, 0), }, };

Except this, looks good to me. Reviewed-by: Isaku Yamahata isaku.yamahata@intel.com

Thanks,

ASSERT_PMC_COUNTING_INSTRUCTIONS(); } static void test_member_deny_list(struct kvm_vcpu *vcpu) {

• struct kvm_pmu_event_filter *f = event_filter(KVM_PMU_EVENT_DENY);

• struct __kvm_pmu_event_filter f = base_event_filter;

• test_with_filter(vcpu, f);
• free(f);

• f.action = KVM_PMU_EVENT_DENY;
• test_with_filter(vcpu, &f);

ASSERT_PMC_NOT_COUNTING_INSTRUCTIONS(); } static void test_member_allow_list(struct kvm_vcpu *vcpu) {

• struct kvm_pmu_event_filter *f = event_filter(KVM_PMU_EVENT_ALLOW);

• struct __kvm_pmu_event_filter f = base_event_filter;

• test_with_filter(vcpu, f);
• free(f);

• f.action = KVM_PMU_EVENT_ALLOW;
• test_with_filter(vcpu, &f);

ASSERT_PMC_COUNTING_INSTRUCTIONS(); } static void test_not_member_deny_list(struct kvm_vcpu *vcpu) {

• struct kvm_pmu_event_filter *f = event_filter(KVM_PMU_EVENT_DENY);

• struct __kvm_pmu_event_filter f = base_event_filter;
• f.action = KVM_PMU_EVENT_DENY;

• remove_event(f, INST_RETIRED);
• remove_event(f, INTEL_BR_RETIRED);
• remove_event(f, AMD_ZEN_BR_RETIRED);
• test_with_filter(vcpu, f);
• free(f);

• remove_event(&f, INST_RETIRED);
• remove_event(&f, INTEL_BR_RETIRED);
• remove_event(&f, AMD_ZEN_BR_RETIRED);
• test_with_filter(vcpu, &f);

ASSERT_PMC_COUNTING_INSTRUCTIONS(); } static void test_not_member_allow_list(struct kvm_vcpu *vcpu) {

• struct kvm_pmu_event_filter *f = event_filter(KVM_PMU_EVENT_ALLOW);

• struct __kvm_pmu_event_filter f = base_event_filter;

• remove_event(f, INST_RETIRED);
• remove_event(f, INTEL_BR_RETIRED);
• remove_event(f, AMD_ZEN_BR_RETIRED);
• test_with_filter(vcpu, f);
• free(f);

• f.action = KVM_PMU_EVENT_ALLOW;
• remove_event(&f, INST_RETIRED);
• remove_event(&f, INTEL_BR_RETIRED);
• remove_event(&f, AMD_ZEN_BR_RETIRED);
• test_with_filter(vcpu, &f);

ASSERT_PMC_NOT_COUNTING_INSTRUCTIONS(); } @@ -567,19 +551,16 @@ static void run_masked_events_test(struct kvm_vcpu *vcpu, const uint64_t masked_events[], const int nmasked_events) {

• struct kvm_pmu_event_filter *f;

• struct __kvm_pmu_event_filter f = {

• .nevents = nmasked_events,
  

• .action = KVM_PMU_EVENT_ALLOW,
  

• .flags = KVM_PMU_EVENT_FLAG_MASKED_EVENTS,
  

• };

• f = create_pmu_event_filter(masked_events, nmasked_events,

• 		    KVM_PMU_EVENT_ALLOW,
  

• 		    KVM_PMU_EVENT_FLAG_MASKED_EVENTS);
  

• test_with_filter(vcpu, f);
• free(f);

• memcpy(f.events, masked_events, sizeof(uint64_t) * nmasked_events);
• test_with_filter(vcpu, &f);

} -/* Matches KVM_PMU_EVENT_FILTER_MAX_EVENTS in pmu.c */ -#define MAX_FILTER_EVENTS 300 -#define MAX_TEST_EVENTS 10

#define ALLOW_LOADS BIT(0) #define ALLOW_STORES BIT(1) #define ALLOW_LOADS_STORES BIT(2) @@ -751,17 +732,27 @@ static void test_masked_events(struct kvm_vcpu *vcpu) run_masked_events_tests(vcpu, events, nevents); } -static int run_filter_test(struct kvm_vcpu *vcpu, const uint64_t *events,

• 	   int nevents, uint32_t flags)
  

+static int do_vcpu_set_pmu_event_filter(struct kvm_vcpu *vcpu,

• 			struct __kvm_pmu_event_filter *__f)
  

{

• struct kvm_pmu_event_filter *f;
• int r;

• struct kvm_pmu_event_filter *f = (void *)__f;

• f = create_pmu_event_filter(events, nevents, KVM_PMU_EVENT_ALLOW, flags);
• r = __vm_ioctl(vcpu->vm, KVM_SET_PMU_EVENT_FILTER, f);
• free(f);

• return __vm_ioctl(vcpu->vm, KVM_SET_PMU_EVENT_FILTER, f);

+}

+static int set_pmu_single_event_filter(struct kvm_vcpu *vcpu, uint64_t event,

• 		       uint32_t flags, uint32_t action)
  

+{

• struct __kvm_pmu_event_filter f = {

• .nevents = 1,
  

• .flags = flags,
  

• .action = action,
  

• .events = {
  

• 	event,
  

• },
  

• };

• return r;

• return do_vcpu_set_pmu_event_filter(vcpu, &f);

} static void test_filter_ioctl(struct kvm_vcpu *vcpu) @@ -773,14 +764,18 @@ static void test_filter_ioctl(struct kvm_vcpu *vcpu) * Unfortunately having invalid bits set in event data is expected to * pass when flags == 0 (bits other than eventsel+umask). */

• r = run_filter_test(vcpu, &e, 1, 0);

• r = set_pmu_single_event_filter(vcpu, e, 0, KVM_PMU_EVENT_ALLOW); TEST_ASSERT(r == 0, "Valid PMU Event Filter is failing");

• r = run_filter_test(vcpu, &e, 1, KVM_PMU_EVENT_FLAG_MASKED_EVENTS);

• r = set_pmu_single_event_filter(vcpu, e,

• 			KVM_PMU_EVENT_FLAG_MASKED_EVENTS,
  

• 			KVM_PMU_EVENT_ALLOW);
  

  TEST_ASSERT(r != 0, "Invalid PMU Event Filter is expected to fail");

e = KVM_PMU_ENCODE_MASKED_ENTRY(0xff, 0xff, 0xff, 0xf);

• r = run_filter_test(vcpu, &e, 1, KVM_PMU_EVENT_FLAG_MASKED_EVENTS);

• r = set_pmu_single_event_filter(vcpu, e,

• 			KVM_PMU_EVENT_FLAG_MASKED_EVENTS,
  

• 			KVM_PMU_EVENT_ALLOW);
  

  TEST_ASSERT(r == 0, "Valid PMU Event Filter is failing");

} -- 2.39.3